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        <div style="margin: 0px 10px 8px 10px"  class="pagetitle">S2-002</div>

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            <div id="ConfluenceContent"><h2 id="S2-002-Summary">Summary</h2>

<p>
</p><p>Cross site scripting (XSS) vulnerability on &lt;s:url&gt; and &lt;s:a&gt; tags</p>

<div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Who should read this</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>All Struts 2 developers</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Impact of vulnerability</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>Injection of malicious client side code</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Maximum security rating</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>Important</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Recommendation</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>Developers using Struts 2 tags should immediately upgrade to <a shape="rect" class="external-link" href="http://people.apache.org/builds/struts/2.0.11.1/">Struts 2.0.11.1</a></p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Affected Software</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>Struts 2.0.0 - Struts 2.0.11 </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Original JIRA Tickets</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p> <a shape="rect" class="external-link" href="http://issues.apache.org/struts/browse/WW-2414">WW-2414</a>,<a shape="rect" class="external-link" href="http://issues.apache.org/struts/browse/WW-2427">WW-2427</a></p></td></tr></tbody></table></div>


<h2 id="S2-002-Problem">Problem</h2>

<p>For both the &lt;s:url&gt; and the &lt;s:a&gt; tag, it is possible to inject parameter values that do not get escaped properly when the tag's resulting URLs are constructed and rendered. The following scenarios are known:</p>
<ul><li>A parameter value included in the construction of a &lt;s:a&gt; result can inject an unescaped double quote, thus being able to inject code in the resulting HTML by escaping the rendered <code>href</code> attribute.</li><li>Both the &lt;s:url&gt; and the &lt;s:a&gt; tag fail to escape &lt;script&gt; tags when <code>includeParams</code> is set to any other value than "none", which can be exploited by calling the containing JSP/action with GET parameters such as <code><a shape="rect" class="external-link" href="http://localhost/foo/bar.action?" rel="nofollow">http://localhost/foo/bar.action?</a>&lt;script&gt;alert(1)&lt;/script&gt;test=hello</code></li></ul>


<h2 id="S2-002-Solution">Solution</h2>

<p>As of Struts 2.0.11.1</p>
<ul><li>Double quotes do get escaped for parameter values used to constuct the output of a &lt;s:a&gt; tag</li><li>&lt;script&gt; tokens do get recursively escaped for parameter values used to contruct the output of &lt;s:a&gt; and &lt;s:url&gt; tags</li></ul>


<p>You can obtain <a shape="rect" class="external-link" href="http://people.apache.org/builds/struts/2.0.11.1/">Struts 2.0.11.1</a> as a drop in replacement for Struts 2.0.11 to get the fixed Struts 2 core library.</p></div>
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